{"vehicle":{"id":"1999_toyota_sienna","year":1999,"make":"Toyota","model":"Sienna"},"code":"P0420","generic":true,"description":null,"bulletins":{"as_of":"2026-10-19","count":3,"bulletins":[{"nhtsa_id":606212,"type":"service_bulletin","type_name":"Service bulletin","date_added":"1999-08-12","date":"1999-06-11","document_id":"EG00299","mfr_campaign":null,"component":"ENGINE AND ENGINE COOLING:ENGINE:GASOLINE","summary":"REVISED INFORMATION TO ASSIST IN THE DIAGNOSIS OF DIAGNOSTIC TROUBLE CODE P0420 INDICATING A POSSIBLE CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD CONDITION. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/606212"},{"nhtsa_id":605187,"type":"service_bulletin","type_name":"Service bulletin","date_added":"1999-06-03","date":"1999-03-11","document_id":"031199","mfr_campaign":null,"component":"UNKNOWN OR OTHER","summary":"BRIEF INFORMATION REGARDING DIAGNOSTIC TROUBLE CODE P0420 INDICATING A POSSIBLE CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD CONDITION. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/605187"},{"nhtsa_id":604746,"type":"service_bulletin","type_name":"Service bulletin","date_added":"1999-05-11","date":"1999-03-12","document_id":"EG00299","mfr_campaign":null,"component":"ENGINE AND ENGINE COOLING:ENGINE:GASOLINE","summary":"SOME VEHICLES MAY EXHIBIT DIAGNOSTIC TROUBLE CODE P0420 INDICATING A POSSIBLE CATALYST SYSTEM EFFICIENCY BELOW THRESHOLD CONDITION. *TT","document":null,"url":"https://open.wenmarpro.com/bulletins/604746"}],"url":"https://open.wenmarpro.com/makes/toyota/sienna/1999/bulletins?code=P0420"},"related":{"components":[],"bulletins":[],"recalls":{"may_apply":true,"recalls":[],"lookup":{"nhtsa":"https://www.nhtsa.gov/recalls","tc":"https://wwwapps.tc.gc.ca/Saf-Sec-Sur/7/VRDB-BDRV/search-recherche/menu.aspx?lang=eng","maker":null}}},"url":"https://open.wenmarpro.com/makes/toyota/sienna/1999/codes/P0420","note":"The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.","attribution":["Contains information licensed under the Open Government Licence – Canada."]}